Water Quality: Analysis Of Four Mile Creek

Emily Bennett Muskegon Community College

April 5, 2014

Stream Analysis: Four Mile CreekThe following tests were conducted on Muskegon Community College campus in the month of November in 2013. Samples were taken from a section of Fourmile Creek that cuts through the forest to the west of the main building. The land surrounding the testing site is primarily residential, however, a car disposal site can be found just north of the campus. The campus has large parking lots to the north and south of the main building. To the east of the campus, there is a large golf course. The campus and its surrounding regions are heavily trafficked areas both by foot-traffic and cars.The testing site of Fourmile Creek is located in a densely forested area populated primarily by deciduous trees and small herbaceous plants. These trees and plants grow right up to and hang over the stream, providing plenty of detritus for the water below. Squirrels and other small mammals, birds, and deer can all be found around campus and near the creek. Four Mile Creek has moderate flow, and is very clear. The chosen test site has an approximate depth of 46 cm, and width is approximately 1.5 meters. Average on-site water temperature was 3.6 degrees Celsius.Two procedures were chosen to test for abiotic factors. The first, a “Low Cost GREEN Water Monitoring Kit” by LaMotte utilizes simple drop-in tablets, which result in a color change in the sample. This color change reaction is compared to a color chart detailing the corresponding test result. The second method chosen was a probe system by Vernier, where electronic sensors read the water samples. For this method, multiple trials were performed for each test. The data collected was averaged and then reported. Nitrate and Phosphate tests required solution standards and the creation of a standard curve to find the corresponding concentrations. After completing both methods, it was found that the Vernier tests resulted in more accuracy in the data than the LaMotte testing kit. However, the LaMotte kit was quicker and easier to work with, especially if samples are to be tested in the field.

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pH Level:

•! Vernier pH probe!! !

Run 1

Run 2

Run 3

Avg.

8.45

8.08

7.91

8.15

•! LaMotte!! Color change after treating the sample with a pH indicator tablet resulted in ! a reading of pH 8.

!!•! Interpretation:!! Although very close to one another, Vernier read the sample to two decimal ! places, therefore producing more accurate data. LaMotte’s data is not to be ! disqualified, however, since the two readings are so close. The pH value of ! streams and lakes is expected to be between pH 7 and 8. The sample test ! of pH 8.15 is considered to be an optimal level for most organisms. ! Although, if this level were to rise to pH 8.2 or above, it can result in ! negative indirect effects on fish due to chemical changes in the water.

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Dissolved Oxygen (DO)!•! Vernier DO probe

DOmg/L

TemperatureCelsius

Atm. Pressuretorr

100% DOmg/L

% Saturation

Run 1

Run 2

Run 3

6.3 6.1 760 12.49 50%

6.3 6.1 760 12.49 50%

6.2 6.1 760 12.49 49.6%

! ! ! ! ! ! ! ! ! ! ! Average %! 49.9%

•! LaMotte

! Temperature (at time of test): 16.3 degrees Celsius

! Color change after treating the sample with a DO indicator tablet resulted in ! the following data: ! ! DO: 4 ppm ! ! % saturation: 41%

•! Interpretation:

! Dissolved oxygen concentration is an important indicator of water quality. ! Oxygen is the key component in cellular respiration not only for humans and ! other terrestrial animals, but also for aquatic organisms. There are many ! sources that contribute oxygen to bodies of water, like atmosphere/surface ! water diffusion, aeration, and photosynthesis of area plants. Also, factors ! including temperature, air pressure, and decaying matter affect ! concentrations.! Data collected by the Vernier dissolved oxygen probe produced more ! accurate results than the LaMotte kit. Both tests resulted in a low DO level. ! A dissolved oxygen saturation level less than 60% is considered poor. ! Possible reasons for this poor rating could be the cold temperature of the ! water or the lack of photosynthesis of plants in the area of the stream.

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B.O.D. (Biochemical Oxygen Demand)

•! Vernier (DO probe)

Initial DOmg/L

Final DOmg/L

BODmg/L

Sample 1

Sample 2

Sample 3

6.3 5.6 0.7

6.5 5.5 1.0

5.6 5.6 0.0

! ! ! ! ! ! ! ! ! Average ! ! 0.57 mg/L

•! LaMotte !! Unfortunately, this test produced an error.

•! Interpretation:!! In a healthy stream, oxygen is replaced faster than it is used by aquatic ! organisms. In some bodies of water, aerobic bacteria decompose so much ! organic material that the oxygen is consumed from the water faster than it ! can be replaced. The resulting decrease in dissolved oxygen in the water is ! what is tested in a Biochemical Oxygen Demand test.!! Samples for the BOD test were tested for dissolved oxygen in three trials ! and then these samples were left capped, in the dark, and at room ! temperature for five days. After five days, the samples were tested for ! dissolved oxygen levels again and the differences were found for each trial. ! The change in DO results in a BOD level. Unfortunately, the stream was ! found to have very low BOD levels possibly resulting from the shallowness ! and cool temperature, and/or the decreased amounts of decaying matter. ! This low test result infers the likelihood of a lack of aerobic bacteria.

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Salinity

•! Vernier (conductivity probe)

Run 1

Run 2

Run 3

Avg.

0.42 ppt

0.42 ppt

0.42 ppt

0.42 ppt

•! LaMotte !! *There is no test available for salinity in this kit.*

•! Interpretation:

! Salinity is a total of all non-carbonate salts dissolved in water. Seawater ! has an average salinity level of 35.0 ppt, whereas freshwater has much ! lower levels of dissolved salts. Even though freshwater on average has ! lower levels, some sources will test higher because of runoff from salted ! roads, irrigation water returned to streams, or chlorinated drinking water. ! The results from Four Mile Creek show an elevated salinity level more than ! likely due to the aforementioned causes. All of these contaminates are in ! close proximity to the testing site. The test result of 0.42 ppt is higher than ! that of some of the elevated salinity level test sites in the United States - the ! Rio Grande River in Brownsville, TX (0.397 ppt) and the Colorado River in ! Andrade, CO (0.343 ppt).

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Total Dissolved Solids (TDS)

! Vernier (conductivity probe)

Run 1

Run 2

Run 3

Avg.

727.7 mg/L

746.4 mg/L

746.4 mg/L

740.17 mg/L TDS

•! LaMotte !! *There is no test available for TDS in this kit.*

•! Interpretation:

! Dissolved solids found in streams include soluble salts yielding ions ! including sodium, calcium, magnesium, bicarbonate, sulfate, and chloride. A ! high concentration of these ions does not necessarily mean that a stream is ! polluted. It is to be expected that these salt species will increase with the ! normal flow of water over mineral-rich rocks and soil. With this in mind, ! however, Four Mile Creek was not observed to have many rocks, and the ! bottom appeared to be mostly sandy. The average reading for TDS in the ! samples was very, very high. Many manmade sources could have ! contributed to this high level. For example, agricultural and/or lawn runoff, ! acidic rainfall, runoff from salted roads, or irrigation water returned to the ! stream. Aquatic life is negatively affected by the dehydration due to the high ! concentration of salts. These salts also adversely affect the taste and quality ! of drinking water.

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Nitrates

•! Vernier (colorimeter)

Reading Absorbance NO2- -N(mg/L)

1

2

3

0.090 0.0051271

0.086 0.0047283

0.089 0.0049277

! ! ! Avg. Nitrate! 0.0049277

•! LaMotte

! Color change after treating the sample with a nitrate indicator tablet resulted ! in the following data: !! ! 5 ppm nitrate

•! Interpretation:

! There are a variety of ways in which nitrate ions make their way into ! freshwater sources. Naturally, these ions will originate in the decomposition ! of plants and animals or legume-plant nitrogen fixation. Manmade sources ! have negatively impacted nitrate levels through agricultural and urban ! runoff, animal feedlots and barnyards, wastewater, and automobile and ! industrial emissions. Not only do high nitrate levels compromise human ! health, but they also contribute to eutrophication of lakes and ponds.! The average nitrate level found in the samples is very low and considered ! below average. This can be due to the particular time of year these samples ! were taken and/or a lack of nitrate sources.

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Phosphates

! Vernier (colorimeter)

Flask Absorbance Total PhosphatesConcentration (mg/L PO4)

Total PhosphatesConcentration (mg/L PO4 -P)

A

B

Avg.

-0.001 0 0

-0.001 0 0

-0.001 0 0

•! LaMotte

! Color change after treating the sample with a nitrate indicator tablet resulted ! in the following data: ! ! 0 ppm

•! Interpretation:

! There are three types of phosphates that are included in reporting for total ! phosphates. Orthophosphates are inorganic forms of phosphate that are ! used in fertilizers and can become a pollutant through runoff. Organically ! bound phosphates are present in human and animal waste as well as ! decaying organic matter. Condensed phosphates are commonly found in ! some detergents and will sometimes be added to water supplies to avert the ! formation of scaling and stop corrosion. Although phosphates are an ! important nutrient for aquatic plants, they require a low percentage of them. ! Therefore, it is easy to overwhelm an aquatic environment with phosphates. ! Just like nitrates, a heavy increase in phosphorus will lead to eutrophication ! of ponds and lakes, decreased DO, and increased BOD. The test trials ! resulted in a total phosphate concentration of 0 mg/L PO4 -P. Levels this low ! can be a limiting factor in plant and algal growth and could be a reason for ! the lack of plant growth and water clarity observed in the creek.

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Conclusion

Overall, the chosen tests for Four Mile Creek show that the water condition can be considered poor quality. The position of the stream in the landscape could be a contributor to the stream’s weakness in abiotic factors. Positioned at the center of the Muskegon Community College campus in what can be considered a shallow gully, the creek is susceptible to mostly runoff. This runoff is most likely saturated by salts used on paved areas during winter and the automobile liquids left behind in these same areas. High salinity concentration and high TDS readings are most likely due to this saturated runoff.

Even in these adverse conditions, however, Four Mile Creek rates good with a pH level of 8, which is particularly supportive of aquatic life. But the pendulum quickly swings back with DO and BOD testing rather negatively, exhibiting an environment that can support only a fraction of what its capacity of aquatic life could be. Unfortunately, salinity concentrations and total dissolved solids tested rather high, also contributing to a unfavorable habitat.

It is suggested that monitoring continue to be performed throughout the seasons and at different sampling sites. Being able to compare data between seasons can indicate seasonal fluctuations and perhaps a more complete picture can be painted as to what pollutants are the major contributors. Sampling from different sites can offer insights as to where larger and lesser concentrations of chemicals may exist. Lastly, data concerning macro invertebrate populations will help in diagnosing pollution sensitivity.

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Resources

•! Low Cost Water Monitoring Kit. LaMotte. Earth Force. <www.lamotte.com>.

•! Johnson, Robyn L., Dan D. Holmquist, Kelly Redding. Water Quality With ! Vernier. Vernier Software and Technology, 2007.

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